Updating deprecation notice for projectFingerprint GraphQL

What does this MR do and why?

Action the decision from this discussion: !118553 (comment 1387688698)

Keep projectFingerprint in GraphQL but return uuid from 16.1

Here we have to avoid doing a breaking change outside of a major release (i.e. a stable API output).

My suggestion would be to create a "remove_project_fingerprint_graphql" feature flag. When turned on, projectFingerprint always returns uuid. When turned off, it returns project_fingerprint if it exists, otherwise it returns uuid. This gives users an option to maintain the stability of the output.

Because we only need the existing project_fingerprint values, we can still remove code that generates and uses project_fingerprint, and any remaining code related to it would be in the model and graphql. So we wouldn't use project_fingerprint, for example, for any comparisons internally; the only use for it would be as an external identifier.

Then, in 17.0, we would be able to remove the remaining code and drop the column.

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